Supplemental fuel feed device



Jan. 5, 1954 D. E. ANDERSON 2,664,871

SUPPLEMENTAL. FUEL FEED DEVICE Filed July 50, 1949 2 Sheets-Sheet l 23 Van L 01" Jan. 5, 1954 D. E. ANDERSON SUPPLEMENTAL FUEL FEED DEVICE 2 Sheets-Sheet 2 Filed July 50, 1949 ruu. duo ,Fmw cur OFF NH WWW 0 203040506 70009010011 IZOBOHOBO MANIFOLD VACUUM INCHES OF WATER n 5 m w 0 FlOW CUT OFF 5 4 25 83. iskrm SQ MAN/FOLD VACUUM INCHES OF WATER H11 5 Patented Jan. 5, 1954 fl hemnson tiredness. I a, Qlevdand,

corporat on-99 3439 Application 1111?;30, 1949, Serial No. 107,720

L Mik -1'27.)

l5 Qls msi 1 This invention relates. to improvements in devices for feeding controlled amounts :of cool.- ant or anti-detonant fluid to the fuel intake of internal combustion engine. Specifically, this invention has to do with a device-for feed:

.ing controlled amounts of anti-detonant fluid .tokan engine, the operation (of which device is controlled in relation to theengine speed as well as to the intake manifold vacuum.

,Itjhas beendiscovered that the lenockingchars 'aeteristi'cs .oIj ihigh compression engines, parties, lax-1v at partsthrottie, vary considerably with speed. .At low speeds detonation occurs from tullgload and low vacuum to part'ioad and relatiyely high vacuum 8 to 12 inches of mercury) while at high speeds and part throttle the tend. -.en,,cv to. knock disappears at a relatively low vac uuin 2 to 8 'inchosfof mercury). At still higher speed there will ihe-no tendency to knock at-all.

"The present devices on the market; for controlling the flow-of anti=detonant to an engine JlSe manifold vacuum imposed on a springfloaded diaphragm .to open and close the valve which controls @the slow. With this type of control, the. flow is started at the same maniiold vacuuin, regardless of engine speed.

type of control is :used on a high compression engine and adjusted so that when the engine is operating at low speed, with part throt- .tle. relatively high vacuum (8 to 12' inches .of mercury), the; tendency to knock will be compensated ior :by an injection of antiedetonant fluid when, when thissame engine is operas-5, ing at high speed and part-throttle conditions,

thesame vacuum (8 to 12 inches of mercury) @mi dflonant iiuid would also he supplied to the although no. knocking tendency isi out. This, of course, becomes wen-y uneconomieal asp considnable amount. of fluid will :be Sup:- n ed that-is not needed. and may also as new. testentireseer-ahon..v

Award as io th teachin s of the. present in: en,- the inflec ion 9i. anti-detoncnt fluid e hi e d ice resnsnsire to two l; eta emu-uracil told filllllil: A inst-conduit; connected into ens res-whi e w thsp ed d load. mime.-

jeotion device. Each oi thenrst and second son.- du-its has orifice of predetermined size, By connecting the first and second conduits to= gether, and using proper size orifice in each branch, a .diiierential pressure may :be obtained which is. then. used to control the diaphragm valvein the injector;

It; is then an important (object of this invention to provide; a device, the operation of which is eontroiied relation -.-to engine speed well as to intake manifold vacuum, rather in relation to manitold vacuum alone, as present devices.

Another object of this inventien is it!) provide .a supplementary iuelfeed device in. which 9. dia: phragm connected. to. a su plementary ruelmer tering valve is subjected on one side -.to atmes: pheric pressure and on the other side. toa com:- .bination of Venturisvacuum pressure and manifoldrsvacuum pressure.

Another object :of this invention is topravide anti=detonant injection device arranged -.to sup ply the proper amount of anti-detonant fluid to suppress knock in high combustion engines under all conditions of operation, such as full load and part load, at alllengine speeds.

Further-features, objects and advantages .of the present invention will become apparent to one skilled in the art from the following detailed description taken in connection with the an! nexed sheets .of'drawings.

On the drawings;

Figure 1 is-aside elevational view, :partly section and partly broken away, of a, supple mentary fuel feeding device constructed accordto the teachings ofthe present invention and shown connected to the engine carburetor and intake manifold connections.

Figure '2 is a vertical sectional view taken through the fuel feeding device of Elgure'l sho'wing asecond set of operating conditionsof the device.

Figure 31 is a chart-showing the relationship between r ienturivvaeuum and manifold vacuum atvariousxspeeds.

Figure. .4 a chart showing the. relationship between a chosen differential pressure and the maniifold vacuumior various engine speeds,

As shown on theldrewingss In 1, the, reference numeral I18 .desig nates generally a supplementary feed device ace cording-to this invention mounted by meansiof an adapter H .-to .a carburetor 18. A throttle block 1|! having a throttle valve 12a. is .disposed between the carburetor intake manifold M of the engine. The adapter I I has a first passage l4 connecting a passage l5 in the body l6 of the feed device ID with a passage ll in the carburetor, and a second passage 19 connecting a passage 28 in the body l6 to a passage 2| in the carburetor. A tubular insert 23 is disposed in the aligned passages l9 and 2| and extends into the Venturi throat portion of the carburetor, while a tubular insert 25 connects the aligned passages 44 and I1 and extends into the throat of the carburetor immediately below the tube 23.

The supplementary fuel feed device 18 includes a main body portion l6 having a recess 21 in the upper surface thereof, with a cover member 28 suitably secured across said recess. A flexible diaphragm 29 is secured at its marginal edges between the body i6 and the cover 28 and extends across the recess 27, defining an upper chamber 38 vented to atmosphere by a vent hole 3| in the cover, and a lower vacuum chamber 33 connected by a tube 34 to a fitting 35 which acts as a vacuum header, the function of which will be described hereinafter.

A cup-shaped lower casing member 31 is held in sealing engagement with the body I6 of the feed device ID, with a gasket 38 of resilient material therebetween, by means of a plurality of cap screws (not shown).

The lower surface of the casing portion 31 has a recess 39 which is enclosed by a closure plate 40 secured to the casing 31 by any suitable means.

A diaphragm 42 is disposed across the recess 39,

having marginal edges secured between the easing 31 and the closure plate 48. The diaphragm,

in connection with the casing 31 and the closure plate 46, defines an upper fluid storage compartment 43 and a lower vacuum chamber 44 which is in communication with the upper vacuum chamber 33 by means of a passageway 45 in the closure plate 48, an aperture 46 in the diaphragm 42, a passageway 41 in the casing 31, an aperture 48 in the gasket 38, and a passageway 49 in the body l6.

An annular hollow float 5| is pivotally mounted in a central chamber 52 of the cup-shaped casing 31 by means of a pin 53 on a depending flange 54 secured to the body IS. A tubular valve housing 55 is threaded into an opening 56 in the body It, having an inner end portion bottomed against the end wall of the opening 56 with a gasket 51 therebetween. The tubular housing 55 has a central chamber 58 with a restricted orifice 59 at one end. The orifice 59 is in alignment with a central passage 68 in the gasket 51 and a passage 6| in the body l6, affording communication between the chamber 58 and a passage 62 connected to a source of anti-detonant fuel.

A valve 63 is slidably disposed in the chamber 58 and has a conical seating surface movable into the restricted orifice 59 and coacting with the edges thereof to control flow of fluid through the housing into the float chamber 52. An arm 5|a of the float 5| acts on the lower end of the valve 63 to mov the conical seating surface of the valve into the orifice 59 to stop the flow of fluid into the chamber 52 when the fluid in the chamber is at the desired level.

A lower boss 64 depending from the body portion l6 extends downwardly into the float chamber 52 and has a central bore or passage 64a in communication with a central passage 65 of substantially larger diameter in an upper boss 66 of the body [6 which extends upwardly into the Vacuum chamber 33. The lower boss 64 terminates in an internally threaded portion 68 arranged to receive the threaded lower end of a tubular vent member 69 which is centrally disposed in the passage 64a and has a central bore 19. A spacer ring H is disposed about the tubular member 69 at the upper end thereof where the passage 64a merges with the larger passage 65 of the upper boss 66. It will thus be seen that the lower end of the passage 65 forms a discharge chamber for the fluid leaving the passage 18. The passage 20 in the block l6 affords communication between the passage 65 and the aligned passages l9 and 2| leading to the Venturi opening of the carburetor.

Since the outer diameter of the tubular vent member 69 is less than the diameter of the bore 64a, there is defined between the vent member and the walls of the bore an annular passage 14 which is in communication with that portion of the float chamber 52 above the shut-off position of the float by means of a slanted passage 15. This upper portion of the float chamber 52 is vented to atmosphere through an opening 16 in the body [6.

To establish communication between the annular passage 14 around the vent member 69 and the central passage 18 of the vent member 68 there is provided a series of radially extending passages 18 in the wall of the vent member 69. The passageway in the center of the tubular vent member 69 is also in communication with the liquid in the float chamber 52 through a restricted passageway or orifice 19 in the threaded end of the tube 69.

Liquid in the float chamber 52 will, of course, pass upwardly through the passageway 19 into the central portion of the tubular vent member 69 and stand at a height therein corresponding to the height of the liquid in the float chamber.

The metering valve of the present invention comprises a segmental conical seating member 82 that extends downwardly from a cylindrical block 83 that is slidably disposed in the enlarged bore 65'of the upper boss 66. The seating member 82 coacts with the upper edges of the hole in the spacer ring H, as shown in Figure 2, to act as a shut-off valve.

The central portion of the diaphragm 29 is held between washers 84 and 85 against a shoulder 88 of the block 83 by means of a peened-over end 88. Thus, flexing movement of the diaphragm 29 will cause the cylindrical block 83 to slide up and down n the central bore 65, moving the conical seatmg member 82 toward and away from the spacer ring 1 I The cylindrical block 83 has a central passage 89 in its upper portion which communicates with a radial passage 95, which in turn is in communication with an annular groove 96 on the outer periphery of the block 83. It will, of course, be recognized that should the peripheral surfaces of the block 83 or the surfaces of the upstanding boss 66 become worn so that liquid can pass upwardly between the boss 66 and the block 83, the suction in the chamber 33 caused by the connection of the chamber 33 with the tube 34 leading to the vacuum connection would cause liquid to be drawn off through these slight openings into the vacuum chamber 33. However, since the annular groove 96 is vented to atmosphere through the passage 89 and the vented chamber 30, the efiect of the vacuum between the surfaces of the block 83 and the boss 66 is broken at this point. Therefore, the vacuum will not be effective to draw liquid up past these surfaces.

A coil spring 9| is disposed in the vacuu mem er -33 between the main ibody 1i and the lowerwasher member flownward movement of the diaphragm '29 and the associated cylindricad bieck M is effected by suction pressure in the suction manifold 3.5 and the-tube 34 which communicates the chamber 33 with the 'blockm. The spring :91 resists the dewm ward movement of the diaphragm and is strong enough to overcome =pu11 of the diaphragm 12.9 when there is iow w-acuurii in the intake manife'ld, thus permitting antiQ-iietonent to be .drawn through the restricted m ifiee =18 and :the passages II, II), l9 and 23, into the fuel intake passageof the engine. Undereonditions efhigh vacuum, the spring permits the diaphragm to 'be ipreg ressiveiy puiled down until the oonicai end 82 of the block 88 is seated on the :top edge of the hole in-the siaaeer ting 1|, thus shutting voff the supply "of anti-detonant fluid.

'fhe iower diaphragm 4-2, which is disposed be:- tween the storage-chamber l3 and the lower vacuum chamber 44, is arranged to flex against the compression of a spring 91 when the vacuum inchaniber M is increased The diaphragm has a, central portion comprising two oppositely dispqssis waahei me b rs 8 d 5 a a d b step m mber 19!! h ch-1e ar anged t abut against aqiiietahle s ep J2! threaded nto the lower e et the e ver pan ma!!! t9 ,...,miit the iiizimaaiii incr ment e the eiaphraeini a 'qi plixe 42 flesedag iiet mean: at pr ng .8L 41mg en ers the storage cam e thyme}; va hall iiheiils Yalve assembly ieeiedi isi-assle A wheel": a nette 93. flee M; a hall m mes; 1&4 aim s ep Pi l 1.05 wh ch the memeei t the ha l. "14 way ise n the atlas 83: he. bell mares may from the. mime L03, fluid will .iiewiiii the ta -a e chamber at a pesaaee mi the bai martian :31 eoainiihicat s th i toree chambe 3 with a messa e m1 in. c mmie tim with passaeeway t5 h hash E: it check veliie assembly :hetwemneeea es ES. and .1!!! anti sme ma a aieeve relve beer Mi he he an ri ee lit e en. esisi th zseefia e iei tbae ieiepeeee e ress ai aeiaga was; e the ake J991= A eprme urged valve meme: it-2 s weesh m a e amer? setsieeii t e part, M a the st p I to permit fluiii te how 120 i. thet erege ehaziibe 43 to the insert 25, at into the in akeer the enginelasip ra i, i i-meme eiia nelja ains ig aenditiqn, the -d aph egiii 142 w ll be flexed ag nst the QQQDIBfiiQQ. 1 the mine 31, Q 3 id wil b stow-d t e chamber it akzeve $11 $11 liraemi Th s q n iqn is n icated ar 2, where the M l valve artly 9p T ea hen a eu d w v c um qesi tion aii e the n ke. m i i ld asgfor example, when the throttle valve is suddenly mev q t we Qp posit on. the sp ing wi l sude ily ercome h weiiiim n ee ii e in the chamber 4. and lie; the diaphragm to ompress he ilu' hmuell th paesaee ,116,110 L5 and. 1 7 7. $1. the insert 251mm the centimeter: hus, thi Jewel ehrae chamb r assembly enemies a supplementary iuel feed s ev. hragi which s moved ,1; by high vacuum. izie a d is re ease a r mee in a predetermin d quantity Qt fluid meme. intake oi the en ine .rees qn e to a sudq ii. weqiti n 9f he ngine hy empleying ser aes 51 at altyieg lead characthe mea ure at 'wlushthis minim my ietm fuel is i-iniectediintc'thec mmer can. be e ulated. "Barthes, by "us ng a z ahiab e deyziee uni-113M. the i amount sf liquid: Mm would he .iemwxi into the tsuenl-y chamber M item be controlled, as whee thelen thiof he st m of the .dianhragm iii ass/whee. to the e timm the itsis a. teatime. ref iinveii ieuthat -the MIMI! um in the line 31 and in the aacuum' members! which is efiective to move the diaph agm 3:9. to Open ielese the metering u hie Q! in time tieii only ef the ereseure in the intake mm.- ield i0; but a so a. :timetion. or vacuum am the 'Ventiiri threat. pevtion oi the wer buretim We attain this diflie ential theiier s provided a fitt ng ditiiwh h $303M. to the fitting :3; ianiiis thrmded :inte. an opening ms intake imaiuieid iiih eh commun cate! with he heel conneetien to the s ixiem downstneam iron; the thtl tfififly' valve.- An. crime mi a iesiet h'mmed ri eeti'ici sl 1M th aeth au h :is fitted intoan inner smoeih po tien Hloftheamntu-re 1%, he by 1% W385, fit,

A second fitting H2 is. .eonneetee t them t n 35 -;by.z meansiof a. iiuhe 1 l3 and is thr a ed in o pening it; in the hody of thfihfiibllfitQL "The opening :1 is. communication with portion at the carburetor by means n t; a 1 1.5 which iearries .a tubular izrifice member ii having a predeterminedfmstriciifid M therein. -'ihus, the fitting 35 which mummo e :tube 13A leadin to the- :ehemher it of the .eunmeznentary tuei teed des lee M is in communica ion throu mitri tee Qri iee hers with both the intake. man-field e and the Ventiiri throat ipelttien-ef the came-mime iaurpese at using hath the entuei ra -him and themaniield :YEL HMm'W mQYQ'EhQ ei ph iaeiii of the feed device is to obtain a differentialipgegp. sure that. will whea en ine sii ed asweil as ma told vacuum :L r LQQQ'QF DInEE the. diashraeminv the ha t i preiiueed n. 'siiv it will be: 9IA that tor a :ml-l leadepemt ee miitiea a typical high en ip ss eii eng ne nozzle both. the Venturi, iiaeuum an the. manito d iian lmi. rease as a the .s eeq. icreeses-. 'l'h iushout the sheer; xangethe Ye itiiri vacuum is leane than. the vacuum the intake mai iielsii The l.ia1-' phiagm v.coxit ol i iii ereiit al 31.49am, hich will be used to the. ncitement (lie-I lira m. 219 iii the fee; de ce 1 ca be ma e to fall. anywh re n be ween th *Vent ri m! ma ifjo lgi yacu im depending upon the relative sizes of the two orifices.

From this chart it will be seen-also that at part loads the Venturi vacuum dcereases from the full load position, while the manifold vacuum increases. At the lower speeds this rate of -de-' crease-is lower than at highspeeds. The partscf the curve below the dotted flow cut-off line indicates the value of the aspirati'ng pressures at which the feed device or iri-jector is opera-tiger A 5 M- H-" h nch s e w i r manifo' d' v cuum the n zle uum is qua to '16 i ches Q wat ef re flo 0f u pl menta y I e iirs. ,At. inc e he e w llbe n n w even though the aspirating pressure is higher than the cut-off point. i

By connecting the Venturi vacuum and the manifold vacuum together and using thepro ieer s z o i e ch. b n a diff rent al pis ur w ll be ob ai ed which c nbe used t cohtrm the d ap r gm a ve i t i iec er- "Re r ng to th ha of "F g r i it will be seen that differential vacuums at various speeds are plotted against manifold vacuum. The

dotted line called flow cut-off indicates, in this chart, the selected differential diaphragm vacuum at which the flow of supplementary fuel will stop. This is the pressure at which the diaphragm valve is set to close. It will be seen that at 30 M. P. H. the valve closes at approximately 133 inches of water manifold vacuum, while at 40 M. P. M. valve closes at 100 inches, and at 60 M. P. H. at 44 inches. At 65 M. P. H. there will be no flow under any condition of engine operation as the differential pressure equals the force of the diaphragm and the spring, and so the valve is closed. Thus, for high speed, low manifold vacuums there will be no supplementary fuel injection. As previously mentioned, for high compression engines the tendency to knock at high speeds disappears at relatively low manifold vacuum. Thus, clearly seen in Figure 4, by properly choosing the differential diaphragm vacuum pressure the supplementary fuel injection will be shut off for high speed operation at relatively low vacuum pressures.

From the foregoing description it will be seen that there is provided in this invention a novel means of controlling the feeding of supplementary fuel to the intake of an internal combustion engine. By using a differential pressure determined by the size of the orifices in a line leading from the Venturi chamber of the carburetor and a line leading from the intake manifold of the engine, the flexing of the diaphragm in response to operation of the engine can be correlated with the speed of the engine as well as the intake vacuum. This invention also provides means depending upon this difi'erential pressure for suddenly injecting an additional charge of supplementary fuel under extreme sudden low vacuum conditions.

Alternately, the auxiliary pump means provided by the diaphragm 42 may be operated solely by manifold vacuum instead of by the differential pressure. In this case a tube I20, shown in dot-dash lines in Figure 1, will connect the vacuum chamber 44 to the intake manifold M.

The term manifold as used herein includes as an equivalent, the intake conduit means beyond the throttle valve in the fuel intake of a single cylinder engine as well as the intake manifold conduit of a multi-cylinder engine.

It will be understood that modifications and variations may be effected without departing from the scope of the novel concepts of the present invention.

7 I claim as my invention:

1. A device for supplementing the fuel feed of a carburetor intake of an internal combustion engine comprising a housing defining a float chamber and having upper and lower substantially central bosses, aligned top and bottom bores extending through said bosses, a restricted orifice in said bottom bore, said top bore providinga discharge chamber at the upper end of said bottom bore, said housing having a discharge passageway in communication at one end with the fuel intake of the engine and the other end in communication with said discharge chamber, said housing having a first diaphragmcovered vacuum chamber subjected to carburetor Venturi vacuum and to engine manifold vacuum, a block connected to said first diaphragm and slidable in said top bore, said block having an end seatable against the top of said bottom bore to close the bore, spring means tending to move said end of the block away from said top of thebottom bore, a second diaphragm-covered vacu-.

um chamber subjected to reduced pressure from said first vacuum chamber, a compartment in said housing above said second chamber and bottomed by the diaphragm of said second chamher, said compartment being in flow communica tion with said float chamber and with said fuelintake of said engine, a spring in said second.

said spring in response to reduction in pressure in said second chamber and effective to close said compartment to permit the diaphragm cover of the second chamber to force fluid from the compartment into said fuel intake of the engine when said spring flexes said diaphragm cover of the second chamber to decrease the size of said compartment.

2. A device for supplementing the fuel feed of a carburetor comprising a casing for containing a body of supplementary fuel, a first conduit for connecting said body of fuel to the Venturi passage of the carburetor, a first valve means located in said first conduit for controlling the flow of supplementary fuel therethrough, a diaphragm for controlling said valve in accordance with differential pressure conditions, one side of said diaphragm being subjected to atmospheric and the other side subjected to carburetor Venturi pressure and to manifold pressure, said differential pressure condition urging said valve to closed position, a spring urging said valve to open position against the resistance of said diaphragm, said spring being sufficient to overcome the resistance of said diaphragm at relatively low vacuum only, a second conduit connecting said body of fuel to the venturi, and second valve means located in said second conduit for controlling the flow of supplementary fuel therethrough, and a second diaphragm arranged to flex in one direction in response to increasing vacuum in said manifold and arranged to be flexed in an opposite direction when said manifold vacuum drops, said flexing in the opposite direction being effective to positively propel a charge of fluid through said second discharge conduit to the fuel intake of the engine.

3. A fluid feed device for delivering supplementary fuel to the intake manifold of an engine which receives its main fuel supply through a carburetor comprising a housing defining first and second fluid storage compartments having discharge conduits arranged for delivering fluid to the intake of the engine and a first and second vacuum chamber, a vacuum-controlled diaphragm in each chamber, a valve in the discharge conduit of said first storage compartment and connected to the diaphragm in said first vacuum chamber for movement therewith to control flow of fluid through the associated discharge conduit, said valve being movable to open said conduit as the vacuum in said first chamber decreases, a spring in said second vacuum chamber resisting movement of the diaphragm therein as it flexes in response to an increase in vacuum in the chamber and arranged to discharge fluid from said second storage compartment when the vacuum decreases a predetermined amount, and means for simultaneously subjecting said first and second vacuum chambers to a differential pressure of a value between the pressure in the Venturi throat of the carburetor and the pressure in the intake manifold of the engine.

In a fuel feed device for supplementing the met feed of a Venturi throat equipped carburetor to the intake manifold of an engine, a housing, a fuel reservoir in said housing, said housing having a vacuum chamber and a passageway in communication with said reservoir and arranged to be connected to the fuel intake of the engine,

a valve in said passageway con-trolling the flow of fuel therethrough, a flexible diaphragm in said housing controlling said valve and having one face subjected to reducedpressure in said vacuum chamber to move the valve toward closed position and the opposite face subject to atmospheric pressure, and means for subjecting said vacuum "chamber to a differential pressure of a value betWe'h the pressure in the Venturi throat of the carburetor and the pressure in the intake inani- Xold of the engine.

5. In a fuel feed device for su plementing the fuel feed of a Venturi throat equipped carburetor to the intake manifold of an engine, a housing, a fuel reservoir in said housing, said housing having a vacuum chamber and a passageway in communication with said reservoir and arranged to be connected to the fuel intake of an engine,

a valve in said passageway controlling the flow of fuel therethrough, a flexible diaphragm in said housing connected to said valve and having one face subjected to reduced pressure in said vacuum chamber for closing the valve under the influence of the reduced pressure and the opposite face subjected to atmospheric pressure, a conduit con- 'Qonduit to a value between the Venturi throat {vacuum and the intake manifold vacuum.

6. In combination with a Venturi throat equipped carburetor and the intake manifold of an engine, a supplementary fuel feed device comprising a housing, a fuel reservoir in said housing, said housing having a vacuum chamber and a passageway in communication with said reservoir and leading exteriorly of said housing, a conduit connecting said passageway to the fuel intake of an engine, a valve in said passageway controlling flow of fluid therethrough, a vacuum responsive diaphragm in said vacuum chamber and connected to said valve for urging the valve into closed position, and a second conduit connecting said vacuum chamber to separate vacuum lines leading respectively from the Venturi throat of the carburetor and from the intake manifold of the engine.

7. In combination with a Venturi throat equipped carburetor, a supplementary fuel feed device comprising a housing, a fuel reservoir in said housing, said housing having a vacuum chamber and a passageway in communication with said reservoir and leadnig exteriorly of said housing, a conduit connecting said passageway to the fuel intake of an engine, a valve in said passageway controlling flow of fluid therethrough from said reservoir, a vacuum responsive diaphragm in said vacuum chamber and connected to said valve to move the valve toward closed position under the influence of vacuum in said vacuum chamber, a second conduit connecting said vacuum chamber to separate vacuum pas- 10 sages leading respectively from the Venturi throat of the carburetor and from the intake manifold of the engine, and orifice members in each vacuum line having openings of predetermined size therethroug'h to proportion the effect of each source of vacuum on the pressure in the vacuum chamber. I

8-. In combination with a carburetor, a supplementary fuel feed device comprising a housing, a fuel reservoir in said housing, said housing having a vacuum chamber and a passageway in communication with said reservoir and leading exteriorly of said housing, a conduit connecting said passageway to the fuel intake of an engine, a valve in said passageway controlling flow of fluid therethrou'gh, a vacuum responsive diaphragm in said vacuum chamber and connected to said valve for biasing the valve toward closed position under the influence of increasing vacuum in said vacuum chamber, and a second conduit connecting said vacuum chamber to the intake manifold of the engine and to a source of vacuum that decreasesas load is removed from the engine. 9. In a feed device for an internal combustion engine including first and second mechanisms for deliveiing fluid to the engine, a vacuum-sensitive control member for placing the second mechanism in operation, a Venturi throat and throttle valve equipped engine intake receiving fuel from both mechanisms, and means venting the control member to both the Venturi throat and the downstream side of the throttle valve thereby creating a differential vacuum for actuating the control member and rendering the mechanism sensitive to engine speed as well as vacuum. I

p 10. A device for supplying auxiliary antiknock fluid to an internal combustion engine, comprising in combination a container for said fluid with a passage opening therefrom to the fuel intake system of the engine, regulating means for controlling the amount of fluid entering said passage, said regulating means being responsive to the differential vacuum created by venting together the vacuum dependent on the amount of air flowing to the induction system of the engine and the vacuum in the air-fuel intake passage, increases of said differential vacuums having the same directional effect on said regulating means, and decreases in said differential vacuums having the opposite directional effect.

11. A device for supplying auxiliary antiknock fluid to an internal combustion engine having throttle means for controlling the main fuel mp ply, comprising in combination a container for said fluid with a passage opening therefrom to the fuel intake system of the engine, regulating means for controlling the amount of fluid entering said passage, said regulating means being responsive to the differential vacuums created by venting together the vacuum obtained before said throttle dependent on air flow and the vacuum obtained after the throttle, increases in said differential vacuums tending to decrease the flow of fluid entering said passage and decreases in said differential vacuums tending to increase said flow of fluid.

12. A device for supplying auxiliary antiknock fluid to an internal combustion engine comprising in combination a container for said fluid with a passage opening therefrom to the fuel intake system of the engine, regulating means for controlling the amount of fluid entering said passage, said regulating means being responsive to the effect of differential vacuums created by venting together the vacuum in the carburetor 11 venturi and the vacuum in the air-fuel intake manifold and tending to increase the flow of fluid through said passage as said differential vacuums decrease and to decrease the flow of fluid through said passage as said differential vacuums increase.

13. A method for changing the antiknock rating of a fuel for an internal combustion engine in accordance with the antiknock requirements of the engine under different operating conditions which comprises supplying to said engine a primary fuel of insuflicient antiknock rating to provide for all operating conditions, and admixing with said primary fuel an auxiliary antiknock fluid when the operating conditions of the engine so require, the amount of auxiliary fluid admixed as aforesaid being controlled by the effect of differential vacuums produced by venting together the vacuum dependent on the amount of air flowing to the carburetor and,

the vacuum in the air-fuel intake manifold, said effect operating in such manner that as said differential vacuums decrease it tends to increase the amount of auxiliary fluid admixed with the primary fuel and as said differential vacuums increase it tends to decrease the amount of auxiliary fluid admixed with the primary fuel.

14. A device for supplying auxiliary antiknock fluid to an internal combustion engine comprising in combination a container for said fluid with a passage opening therefrom to the fuel intake system of the engine, regulating means for controlling the amount of fluid entering said passage, said regulating means being responsive to the combined effect of the vacuum in the carburetor Venturi and the vacuum in the air fuel intake manifold and tending to increase the flow of fluid through said passage as either of said vacuums decreases and to decrease the flow of fluid through said passage as either of said vacuums increases, a diaphragm-covered chamber in said container vented to said regulating means, a compartment communicating with said container bottomed by the diaphragm cover for said chamber, check valve means accommodating flow of fluid from said container into said compartment, means providing a discharge passageway for said compartment and opening therefrom to said fuel intake system of the engine, and a spring urging the diaphragm cover of said chamber to decrease the size of said compartment for forcing fluid therefrom through said passageway whenever said combined effect of the vacuum is insufficient to hold the diaphragm cover for collapsing said spring.

15. In a feed device for an internal combustion engine including first and second mechanisms for delivering fluid to the engine, a vacuumsensitive control member for placing the second mechanism in operation, a Venturi throat and throttle valve equipped engine intake receiving fuel from both mechanisms, and means venting the control member to both the Venturi throat and the downstream side of the throttle valve thereby creating a differential vacuum for actuating the control member, a diaphragm pump communicating with said engine intake and receiving fluid from said second mechanism, and means venting the diaphragm pump to said differential vacuum for actuating the pump to receive fluid from the second mechanism whenever the differential vacuum is above a predeterminend amount and for discharging the fluid from the pump into the engine intake whenever the vacuum decreases below said predetermined amount.

DAVID E. ANDERSON.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,316,327 Garretson Apr. 13, 1943 2,377,607 Bodine June 5, 1945 2,447,791 Barfod Aug. 24, 1948 2,477,481 Ericson July 26, 1949 2,551,719 Ball May 8, 1951 2,572,169 Mallory Oct. 23, 1951 2,616,404 Bartholomew Nov. 4, 1952 

